US3008384A - Devices for handling folding box blanks - Google Patents

Description

Nov. 14, 1961 c. J. PIERCE, JR

DEVICES FOR HANDLING FOLDING BOX BLANKS Filed Sept. 15, 1959 5 Sheets-Sheet 1 INVENTOR. C/1es2er J. Pierce, JR

ATTORNEY Nov. 14, 1961 c. J. PIERCE, JR

DEVICES FOR HANDLING FOLDING BOX BLANKS 5 Sheets-Sheet 2 Filed Sept. 15, 1959 Nov. 14, 1961 c. J. PIERCE, JR

DEVICES FOR HANDLING FOLDING BOX BLANKS 5 Sheets-Sheet 3 Filed Sept. 15, 1959 Fig. 4

INVENTOR. C/Ies/er Pie/c e, JI:

M ATTORNEY Nov. 14, 1961 c. J. PIERCE, JR

DEVICES FOR HANDLING FOLDING BOX BLANKS 5 Sheets-Sheet 4 Filed Sept. 15, 1959 VA C. PUMP INVENTOR. C/Iesfer J. Pierce; Jr: BY

ha-MA '5. 4 1? 0 ATTORNEY Nov. 14, 1961 c. J. PIERCE, JR

DEVICES FOR HANDLING FOLDING BOX BLANKS Filed Sept.

5 Sheets-Sheet 5 INVENTOR. C/Iesfer J. Pierce, Jr. BY

ATTORNEY 3,098,384 DEVICES FOR HANDLHNG FOLDING BOX BLANKS Chester J. Pierce, J12, Paio Alto, aiif., assignor, by mesne assignments, to Atlas General Industries, Inn, a corporation of Massachusetts Filed Sept. 15, 1959, Ser. No. 840,141

12 Claims. (Cl. 93-49).

This invention relates to improvements in machines for folding fiat box blanks into box form.

Box folding machines basically comprise a magazine in which flat box blanks are scored, a feeding mechanism which removes the box blanks one by one from the magazine, and a folding mechanism which folds the various panels and flaps of the blank into hollow box form.

A preferred type of folding mechanism is the plungerand-die type in which a plunger engages a box blank and forces it through a forming die. During passage of the blank into and through the die various blank portions are gluelessly interlocked, adhesively attached, or otherwise secured together so that a completed box emerges from the die.

Machines of the plunger-and-die type have the advantage of requiring relatively little fioor space in relation to their capacity or output, and the invention may be employed with advantage in machines of this type, although the invention oifers similar advantages in machines in which a blank is moved by a conveyor past folding and securing devices which are arranged alongside the conveyor track.

A preferred form of blank feeding device is the suction feeder in which one or a plurality of suction cups grasp a blank, remove it from the end of the stack of blanks in the magazine and transport it to the folding mechanism, be it of the plunger-and-die type or of the conveyor type.

A suction feeder offers the advantage of not only removing blanks one at a time dependably, but is also capable of depositing the blank in the forming mechanism in an accurately defined position, so that subsequent aligning of the blank with respect to the forming mechanism, for example by jogging, is not necessary. Accurate alignment of the blank with respect to the forming mechanism is highly important in plunger and die machines in which, for example, the plunger must strike a certain blank panel in a precisely defined position in order to avoid misshaping of the box.

It is readily apparent that the greater the number of folding operations to be performed, the longer must be the path of the blank through the die and consequently the longer the stroke of the plunger. A long plunger stroke is undesirable because it limits the output rate of the machine in which the plunger velocity must be maintained below certain practical lirnits in order to avoid balancing problems, acceleration and deceleration problems and other problems connected with rapid movement of oscillating masses such as the plunger.

The present invention provides an improved blank feeding mechanism of the suction cup type which not only removes box blanks one by one from the blank magazine, but also performs certain prefolding, flexing, prebreaking or cut opening operations on the blank while the blank is in transit between the magazine and the box forming section of the machine.

In the box blank feeding devices embodying the present invention the flat blank which is held by the suction cup or cup-s is also at an appropriate moment engaged by a blank engaging element which bears against the blank at a selected point or points spaced from the cup or cups. A relative motion between cup and element then moves the blank engaging element beyond the plane defined by the face of the suction cup whereby the blank is flexed, bent or prefolded.

The relative motion between a cup and a blank engaging element is related to the travel of the feeder between the pick-up station, for example the blank magazine, and the blank deposit station, for example the folding or forming die.

Since the suction cups normally travel along a more or less complex path controlled by cams and lever mechanisms, the relative motion between the cup or cups and the blank engaging element or elements may be'produced in the same way.

However, a preferred technique is to utilize pneumatics, more particularly the vacuum which is applied to the cups at certain periods.

Shortly prior to the approach of a suction cup to the blank magazine, vacuum is applied to the cup. A certain sub-atmospheric pressure thus exists in the duct connecting the cup with a source of vacuum, for example a pump. a i

As long as no blank adheres to the cup the vacuum is a low one, for example of the order of 500 mm. of mercury, due to the fact that atmospheric air enters through the cup.

As soon as the cup grasps a blank and shuts off the flow of air into the vacuum duct the vacuum becomes relatively high, for example 50 mm. of mercury or'less. The sudden drop in pressure may be utilized to operate a pneumatic servo-motor which then retracts the cup or cups, or projects the blank engaging element or elements beyond the cup or cups.

The servo-motor may be of the piston or plunger variety, or it may preferably be a collapsible bellows or multiple cup structure which is associated with the blank grasping suction cup.

When the blank is to be dropped at the end of the feed stroke the vacuum is shut off and the interior of the cup or cups is brought into communication with the atmosphere. This restores the servo-motor to its normal rest position corresponding to a position of the blank engaging elements behind the cup face. The feeder then returns to the pick-up station and the cycle is repeated.

Turning now to the specific purposes of the invention, it is frequently desirable toprefold certain flaps or panels with respect to the substantially flat remainder of the blank so as to initiate folding operations which are later completed by the box forming mechanism, or in order to move certain flaps or panels out of the way of other flaps or panels which are first folded by the box forming mechanism. The construction of the box forming mechanism, for example the die, can be greatly simplitied, the plunger stroke can be reduced and the machine capacity can be increased if certain folding operations are performed before the blank arrives at the die. The

present invention accomplishes this.

Frequently it is desirable to stiffen the blank in order to insure folding in certain directions but not at right angles thereto. This may be done by flexing or arching the blank. An arched blank resists folding in a direction in which the fold line would become a chord.

It is further desirable in many instances to prebreak certain folding scores of the blank in order to facilitate the subsequent formation of the box to insure a proper sequence of folding operations. This may be accomplished by the present invention which may be employed to prebreak selected folding scores during passage of the blank from the magazine to the folding section.

In certain box blanks extensions of certain flaps or panels are cut from the body of other flap-s or panels anticul'ated to the certain flaps or panels along folding scores, for example. When the blank is folded at these scores, the aforesaid extension must not be folded, but should remain fiat. In this connection the problem -is presented of preventing the extensions from moving with the flaps or panels which are being folded and with which the extensions have frictional engagement alongtheir cut edges. V V t The present invention may advantageously be employed in solving this problem by flexing the blank during transit from the magazine to the folding section so as to separate the outer cut edges of the extension from the inner cut edges of the flap or panel from which the extension is cut, thereby eliminating frictional engagement along the cut edges.

Other uses of the invention will suggest themselves 7 from the study of the following description of specific combinations of elements embodying the invention accompanied by drawings showing, for the purpose of illustration, preferred embodiments of the invention. The invention also resides in certain new and original features of construction and combination of elements hereinafter set forth and claimed.

Although the characteristic features of this invention 7 which are believed to be novel will be particularly pointed out in the claims appended hereto, the invention itself, J its objects and advantages, and the manner in which it may be carried out, may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of it in which:

FIG. I is a perspective view of a box assembly machine incorporating the invention, the machine being shown in the initial phase of operation of the blank folding feeder;

FIG. 2 is a perspective view of the machine of FIG. 1, the machine being shown in the final phase of operation of the blank folding feeder;

FIG. 3 is a plan view of a modified flat blank;

FIG. 4 is a perspective view showing the blank after a prefolding operation performed according to the invention;

FIGS. 5 and 6 are diagrammatic views of basic feeder arrangements embodying the invention;

FIG. 7 is a vertical cross section through a preferred form of suction cup and servo-motor which may be employed; and

7 FIG. 8 to 11 are schematic illustrations of different embodiments of the invention.

In the following description and in the claims various details will be identified by specific names for convenience. The names, however, are intended to be generic in their application. Corresponding reference characters refer to corresponding parts in the several figures of the drawings.

The drawings accompanying, and forming part of, this specification disclose certain details of construction for the purpose of explanation of broader aspects of the invention, but it is understood that structural details may be modified in various respects without departure from the principles of the invention and that the invention may be incorporated in other structural forms than shown.

The drawings illustrate the invention as applied to a box blank forming machine of the plunger-and-die type in which a feeding mechanism withdraws a fiat box blank from a blank magazine, transports it to a blank folding die and deposits it on the die in a position in which it will be struck by a plunger which then forces the blank through the die.

The particular feeding mechanism illustrated in the drawings and its geometry is described in great detail in the prior patents to T. R. Baker et 211., 2,624,249 of January 6, 1953, and to F. M. Lefief, 2,805,06t), dated September 3, 1957. It will therefore be possible to limit this description of the feeder mechanism to matters essential to an understanding of the present invention.

FIGS. 1 and 2 show a stack of fiat blanks B resting on cylindrical rails 12 of a blank magazine 13.

A blank folding plunger 14 is mounted by means of a bracket 15 on a horizontal drive bar 16 which moves up and down and causes the plunger to move into and out of a folding die 17 comprising numerous blank folding elements 18 supported in a die frame 19. A conveyor 20 is visible below the die. It carries completed folding box structures away which are ejected from the bottom of the die. I

A feeding mechanism is timed in its operation with the up and down movement of'the drive bar 16 and'the plunger 14 attached thereto. The principal elements of the feeder mechanism are best seen in FIG. 2.

A transverse feeder bar 21 is supported between double-armed levers 22 secured to the bar at 23. The opposite end 24 of the double-armed lever carries a pair of parallel plates 25 straddling a roller 26 on the machine frame 27 in such a way that each lever 2-4 may pivot about, as well as slide longitudinally with respect to, the roller 26.

The central portion of the double-armed lever 22 pivotally engages at 28 one arm 29 of a bell crank lever 30 for oscillation on the machine frame at 31. The other arm 32 of the lever 30 has a connecting rod 33 attached to it at 34 leading to a further bell crank lever 35 from which still another connecting rod 36 leads to the drive mechanism which moves the horizontal drive bar 16 up and down. Details of the drive mechanism are illustrated and described in the aforementioned Leiief patent.

Individual blanks B are grasped by suction cups 37 at the bottom end of a projectible and retractable servo mechanism or bellows 38 on a mounting bar 39. The bar 39 is attached to the transverse feeder bar 21 by arms 40. Flexible tubing 41 leads from the suction cups 37 and servo mechanism 38 to a vacuum pump 42 via a control valve 43 operated i-nti-rned relationship with the motion ofrthe bell crank lever 30 on which it may be mounted (see also FIG. 5).

In addition to the cups 37 the mounting bar 39 carries blank engaging elements 44 whose ends are so positioned with respect to the plane of the face of the suction cups 37 that the plane of the suction cups lies in front of the ends of the blank engaging elements 44 when the cups 37 are extended, but behind the ends of the blank engaging elements when the cups are retracted. In the latter instance, the elements 44 act like pushers and deflect certain portions of the blank B below the plane of the remainder of the blank grasped by the suction cups '37. As a result, certain prebreaking, prefolding, cut opening or flexing operations are performed.

In view of the fact that FIG. 2 shows more details of the actuating mechanism of the feeder than FIG. 1, the return stroke of the feeder will first be described. At the beginning of the return stroke the suction cups are vented to the atmosphere in a manner later to be described. As a result, the cups release the blank which remains on the die as the bell crank levers begin to pivot counterclockwisely about pivots 31. The transverse feeder bar first rises in a substantially vertical direction, accompanied by a sliding motion of the end 24 of the lever 22 with respect to the roller 26. The sliding motion gradually decreases as the arm 24 begins to pivot about the roller 26. The feeder bar now swings away from the die and moves toward the magazine. The final phase of the bar motion again involves a sliding motion of the end 24 of the lever 22 which is now nearly horizontal as the feeder approaches the magazine. As the cups move toward the magazine, the valve 43 (FIG. 4) is moved into the position in which vacuum is applied to the cups. Consequently the cups attach themselves to the first blank B atmospheric air into the suction cups is prevented and the pressure inside the suction line 41 drops. The reduction in pressure causes the servo mechanism to retract the cups beyond the plane of the ends of blank engaging elements 44. The elements 44 now depress internal panel portions 45 of the blank below the plane of the remainder of the blank to which the cups 37 are attached. Thus, a folding operation is performed by the feeder immediately after the suction cups attach themselves to the blank and before the blank reaches the die.

In the illustrated form of blank the panel portions 45 constitute transverse partitions of a cellular divider structure to be formed. It is necessary to separate their borderingcut edges from frictional contact with the remainder of the blank so that subsequent folding operations performed on the remainder of the blank will not carry the panel portions 45 with them by frictional engagement.

The feeder carries the prefolded blank to the die and deposits it on certain blank folding elements 18 to initiate the upward folding of lateral portions of the blank,.in distinction from the downward deflection imparted to the portions 45 by the elements 44.

The prefolding, prebreak-ing, or flexing operations may be more complex than the operations illustrated in FIGS. 1 and 2. FIG. 3 shows a flat blank of a multicellular structure and FIG. 4 shows the same blank after performance of certain prefolding, out separating, and panel flexing operations.

The blank B comprises a central bottom portion 47 to which lateral wall portions 48 and 49 are articulated along lateral fold lines 50 and 51.

Transverse partition panels 52 are cut from the stock of the central and of the lateral blank portions by internal cuts 53 starting and ending at the ends of transverse fold lines 54 along which the transverse partitions remain articulated to the central bottom portion 47. A terminal transverse partition panel 55 is articulated to the end of the central bottom portion along a transverse fold line 56. Cuts 57 separate the lateral portions of the terminal panel 55 from the remainder of the blank.

The blank is gripped by five suction cups at circular areas 58. Blank engaging elements of three types are adapted to engage the blank along areas 59, 69 and 61. The blank engaging elements which engage the blank at areas 59 may resemble the elements 44- shown in FIGS. 1 and 2. In addition the blank is engaged by elements whose cross section corresponds to the areas 61 The latter elements bear down upon the central bottom portion 47 of the blank. A third type of element of somewhat greater width engages the terminal transverse partition 55 at 61 and depresses it with respect to the central bottom portion 47 which is lifted by the cup at the area 58 adjacent the partition 55.

As the feeder approaches the flat blank in the magazine, the suction cups extend in front of the plane in which the blank engaging elements terminate so that the suction cups can grasp the blank without interference by the blank engaging elements. Immediately after the suction cups attach themselves to the blanks, the suction cups are retracted and convert the blank into the shape shown in FIG. 4.

The terminal transverse partition panel is downfolded along its fold line 56. The central portion of each of the remaining transverse partitions 52 is raised above the plane of the remainder of the blank, but the lateral portions of the transverse partitions are depressed below the plane of the blank. The transverse partition panels are flexed, but not creased since in the completed structure each transverse partition is flat and lies normal to both the lateral walls 48 and 49 and to the bottom 47.

It is readily apparent from FIG. 4 that a separation of all cut edges takes place so that the transverse partitions are not disturbed during a subsequent folding operation performed by a plunger on the laterm walls 48 and 49 as the plunger passes through a die.

When the blank B is deposited on the die, the .upfolding of the lateral walls 48 and 49 is initiated in a similar manner as illustrated in FIG. 2. The plunger then strikes the blank along the central bottom area 47 and forces the blank into the die. As a result, the lateral walls 48 and 49 are erected with respect to the bottom panel 47 and substantially simultaneously, or immediately thereafter, the transverse partition panels are upfolded along their fold lines 54 until they are vertical with respect to the bottom panel. in the completed structure cuts 62 at the base of each V frictionally engage edges 63 of the lateral walls 48 and 49 and maintain the structure in assembled position.

Various combinations of blank engaging elements with suction cups and their associated servo mechanism may be chosen, depending on the shape of the blank and the operations to be performed. A few such combinations are shown in FIGS. .5, 6, 8, 9, l0- and 11. In the arrangement shown in FIG. 5 a pair of suction cups 37 straddle blank engaging elements 44. Normally, the extended suction cups project beyond the ends of the blank engaging elements 44 so as to be able to pick up a blank at the magazine. When the servo mechanism 38 retracts the cups 37, the engaged portions of the blank B are folded or flexed upwardly with respect to the central portion of the blank.

In the arrangement of FIG. 6 the blank engaging elements 44 straddle the suction cups 37. Actuation of the servo mechanism 38 causes the central portion of the blank 13.; to rise so that the end portions of the blank are flexed or folded downwardly.

A particularly simple combination of a suction cup and a servo mechanism is shown in FIG. 7. The device comprises a suction cup 37 mounted on a metal bushing 64 having a bottom flange 65. A second cup 66 is mounted on the bushing 65 and faces in the opposite direction. The cup 66 is held in place by a top flange 67 of the bushing 64. The bushing 64 is slidable on a hollow central stem 68 having an enlarged head 69 bearing against an internal shoulder 70 on the head 69, thereby limiting the forward movement of the cup 37.

The threaded end 71 of the stem 68 is screwed into a hollow nipple 72 on which a further cup 73 is seated between flanges 74 and 75 and lies face to face with the rim of the cup 66. a

The nipple 72 is connected to a suitable suction line with the result that atmospheric air enters through the bushing 64 of the suction cup 65 and passes through the hollow stem 68 and the nipple 72 into the suction line.

The interior chamber 76 formed by the cups 66 and 73 is in communication with the air passage through the stem 68 by a hole 77.

When the inflow of atmospheric air is interrupted by a blank attaching itself to the suction cup 37, the pressure inside the cup chamber 76 drops and the cups 73, 66 collapse to a certain degree thereby retracting the suction cup 37. The movement of the suction cup 37 is guided by the bushing 64 sliding on the stem. The retracting motion continues until the top flange 67 of the bushing 64 strikes the flange 74 of the nipple.

The cups 37, 66 and 73 may be made of natural or synthetic rubber. The resiliency of the cup material causes the cups to return to the normal extended position, when the pressure inside the chamber 76 is made equal to the surrounding atmospheric pressure.

Referring 'to FIG. 5 the vacuum line 41 whose flow resistance may be augmented by a constricted line portion 78 leads to a valve 43 having a vent port 79 to the atmosphere. In the position in which the valve 43 is shown, vacuum is applied to the cups 37 and to the collapsible servo cup devices 38 which are retracted.

When the valve 43 is turned a quarter turn in clockwise direction, the line to the vacuum pump is interrupted and the interior of the cups 357, 38 is vented to the atmosphere. Air enters through vent port 79 and causes the suction cups 37 to release the blank immediately. The return of the servo mechanism to the normal extended position may be retarded by restricting the air flow into and out of the cup chamber 76 (see FIG. 7). The hole 77 may be made small enough in relation to the volumetric capacity of the chamber 76 to produce the desired delay during the retracting and extending movement of the device.

In the device shown in FIG. 8 the servo mechanism comprises a bellows 80 guided by an arm 81 hingedly mounted to the blank engaging stem and pad 144 at 82. A spring- 83 is employed to return the suction cup 37 and arm 81 to the extended position and a screw 84 serves to limit the retracting movement. j

In the device shown in FIG; 9 a blank engaging plate 244 is straddled by suction cups 37 A common servo mechanism for the two cups 37 comprises a cylinder 85 containing a piston 86 urged outwardly by a spring 87. A beam 88 connected to the piston 86 by a stem 89 and connected to the cups 37 by links 90 operates both caps 37 simultaneously. Arms 91 pivoted at 92 ide the cups 37. a

The device of FIG. may be considered a reversal of the arrangement of FIG. 9. A pair of pushers 344 straddle the suction cups 37 mounted on a yoke 93. Operating levers 94 and links 95 retract and project the pushers 344 in accordance with the movement of the piston 86 in the servo-cylinder 85.

In the arrangement shown in FIG. 11 the suction cups 37 are mounted on posts 96 by links 97 normally maintained in line with theposts 96 by flat springs 98 but permitting the cups to tilt slightly, as shown. A central servo- motor 85, 86, 87 operates a projectible and retractable pusher plate 344 by arms 194. The plate 344 carries a central cylindrical guide bushing 99. within which the stem 89 slides, thereby maintaining the plate 344 normal to the servo-motor axis.

What is claimed is: a

1. In a folding box blank erecting machine, the combination of a carrier movable between a first blank pickup station and a second blank deposit station; a suction cup member; a blank deflecting member; means for mounting one of said members fixedly on said carrier;

means for movablyrmounting the other member on said carrier, the freedom of movement being sufficiently great that in one position the plane defined by the face of the suction cup lies beyond the blank deflecting member, so that a cup held blank clears the blank deflecting member, and that in the other position the blank deflecting member extends beyond said plane to flex the portion of the blank engaged by said blank deflecting member into an angular position with respect to the cup held portion of the blank; means timed with the travel of said carrier between said stations for periodically applying vacuum to said cup and relieving said vacuum; and means responsive to said vacuum for moving the movable member into said other position.

2. In a folding box blank erecting machine, the combination of a blank carrier movable between a blank magazine and a blank deposit station; a suction cup; a. fixed blank deflecting member on said carrier, means for mounting said cup on said carrier with freedom of move- 'ment from a first position in which the plane defined by the face of the suction cup lies beyond the blank defleeting member, so that a cup held blank clears the blank deflecting member, into a second position in which the blank deflecting member extends sufficiently far beyond said plane to flex at least a portion of the cup held blank out of its original flat shape; means for biasing said cup towards said first position; means for periodically applying vacuum to said cup; and a bellows responsive to vacuum applied to said cup for retracting said cup into said second position.

3. In a folding box blank erecting machine, the combination of a blank feeder movable between a blank magazine and a folding die; a suction cup member; a blank deflecting member; means for supporting said members on said feeder with freedom of motion relatively to each other from a first position in which the cup pro jects beyond the blank deflecting member into a second position in which the blank deflecting member projects beyond the cup sufliciently far to move the cup held portion of the blank out of the plane of that portion of the blank which is engaged by said blank deflecting member thereby flexing the two last named blank'portions into an angular relationship; means for periodically applying vacuum to said cup member; and a pneumatic servomotor timed with respect to the application of vacuum for moving said two'members relatively to each other from the said first position into said second position.

4. In a folding box blank erecting machine; the combination of a carrier movable between a blank magazine and a folding die; a suction cup member; a blank deflecting member; means for supporting said members on said carrier with freedom of motion relatively to each other from a first position in which the cup projects beyond the blank deflecting member into another position in which the blank defieotingrnember projects beyond the cup sufliciently far to move the cup held portion of the blank out of the plane of that portion of the blank which is engaged by said deflecting member; means for biasing at least one of said members towards the said first position; means for periodically applying vacuum to said cup member; and a pneumatic servo-motor responsive to the vacuum at the cup for periodically reversing the relative position of said two members in opposition to said biasing means.

5. In a folding box blank erecting machine comprising a magazine for storing flat blanks and a box forming plunger and die remote from said magazine, the combination of a carrier movable back and forth between said magazine and said die for transporting blanks to said die; a suction cup member mounted on said carrier; a blank deflecting member mounted on said carrier, said members having freedom of movement relatively to each other from a first position in which the cup projects beyond the blank deflecting member into a second position in which the said deflecting member projects beyond the cup sufliciently far to move the cup held portion of the blank out of the plane of that portion of the blank which is engaged by said deflecting member thereby flexing the two last named blank portions into an angular relationship; means controlled by said carrier motion for applying vacuum to saidcup; and a pneumatic servo-motor responsive to the vacuum at the cup for moving said members relatively to each other from said first position into said second position.

6. In a folding box blank erecting machine comprising a magazine for storing flat blanks and a blank forming station remote from said magazine, the combination of a carrier movable back and forth between said magazine and said station for transporting blanks to said station; a suction cup member mounted on said carrier; a blank deflecting member mounted on said carrier, said members having freedom of movement relatively to each other from a first position in which the cup projects beyond the blank deflecting member into a second position in which the blank deflecting member projects beyond the cup sufliciently far to deflect the blank portion which it engages out of the plane of the cup held portion of the blank;

means controlled by said carrier motion for periodically applying vacuum to said cup; and means responsive to the presence and absence of a blank on said cup for moving said members relatively to each other into the 3,oos,ssa

motion with respect to said carrier; 21 fixed blank deflecting member mounted on said carrier in a position in which its end lies behind the projected cup but projects beyond the retracted cup suhiciently far to flex the blank portion which said member engages out of the plane of the cup-held blank portion; means, including a duct, for applying vacuum to said cup; and a pneumatic collapsible bellows responsive to the vacuum in said duct for retracting said cup against the action of said biasing means.

8. In a folding box blank erecting machine, the combination of a carrier movable back and forth between a blank magazine and a blank deposit station; a suction cup mounted on said carrier with freedom of projecting and retracting motion with respect to said carrier; means for guiding said cup along a predetermined path of motion; a blank deflecting member fixedly mounted on said carrier in a position in which its end lies behind the projected cup but projects beyond the retracted cup sufficiently far to flex the blank portion which said member engages out of the plane of the cup-held blank portion; means, including a duct, for applying vacuum to said cup; and pneumatic servo means between aid cup and said carrier acted upon by the vacuum in said duct for retracting said cup upon the decrease in pressure resulting from a blank closing the interior of the cup against the atmosphere.

9. In a folding box blank erecting machine, the combination of a carrier movable back and forth between a blank magazine and a blank deposit station; a suction cup mounted on said carrier; a blank deflecting member mounted on said carrier with freedom of projecting and retracting motion with respect to the suction face of said cup; means, including a duct, for applying vacuum to said cup; biasing means for normally maintaining said member in retracted position behind the face of the cup; and a pneumatic servo-motor responsive to the vacuum in said duct for projecting said member beyond said cup against the action of said biasing means sufliciently far to flex the portion of the blank engaged by said member out of the plane of the cup-held portion of the blank.

10. In a folding box blank erecting machine, the combination of a carrier movable back and forth between a blank magazine and a blank deposit station; members of two kinds on said carrier the member of a first kind being a suction cup, the member of the second kind being a blank deflecting member, two members of one kind straddling at least one member of the other kind; mounting means for mounting said members on said carrier for freedom of projecting and retracting motion of the members of one kind with respect to the other kind; means including a duct, for applying vacuum to suction cups; biasing means for normally maintaining the blank deflecting member in a position behind the cup member; and a pneumatic servo-motor responsive to changes in vacuum in said duct for moving said members into the opposite position in which the cup member lies behind the blank deflecting member when, as a result of attachment of a blank to the cup, the vacuum is increased, the freedom of motion being sufiicien-tly great to flex the portion of the blank engaged by the deflecting member out of the plane of the portion of the blank grasped by said cup.

11. In a folding box blank erecting machine, the combination of a blank feeder movable back and forth between a blank magazine and a blank deposit station; a suction cup mounted on said feeder with freedom of projecting and retracting motion with respect to said feeder; a pair of blank deflecting members mounted on said feeder to either side of the cup and in a position in which the blank engaging surfaces of the deflecting members project beyond the retracted cup, but lie behind the projected cup, the motion of the cup being suflicient to move the cup-held portion of the blank out of the plane of those portions of the blank which are engaged by said deflecting members, thereby flexing the blank out of its original flat shape; means, including a duct, for applying vacuum to said cup; biasing means for normally maintaining said cup in projected position; and a pneumatic servo-motor responsive to the vacuum in said duct for retracting said cup against the action of said'biasing means.

12. In a folding box blank erecting machine, the combination of a blank feeder movable back and forth between a blank magazine and a blank deposit station; a pair of suction cups mounted on said feeder with freedom of projecting and retracting motion with respect to said feeder; a blank engaging member mounted on said feeder between said cups in a position in which its blank deflecting surface lies behind the projected cups but in front of the retracted cups, the motion of the cups being sufficient to move the cup-held portions of the blank out of the plane of that portion of the blank which is engaged by said deflecting member, thereby flexing the blank out of its original flat shape; means, including a duct, for applying vacuum to said cups; biasing means for normally maintaining said cups projected; and pneumatic servomotor responsive to the vacuum in said duct for retracting said cups against the action of said biasing means.

References Cited in the file of this patent UNiTED STATES PATENTS 2,743,651 Wilcox May 1, 1956 2,869,439 Wilcox Jan. 20, 1959 2,887,022 Lubersky et a1. May 19, 1959 UNITED STATES PAT CERTIFICATE OF C Patent N0. 3 0O8,384

ENT OFFICE ORRECTION November- 14 1961 Chester J. Pi erce Jr, It is hereby certified that err ent requiring 00 or appears in rrection and that th corrected below.

the above e said Letters numbered pet- Patent sh ould read es Column l0 line 34, line 36, for

for "engaging" read def "deflecting" lecting read engaging Signed and sealed this 1stday of May 1962.

(SEAL) Attest:

ERNEST w, SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents

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